1. Field of the Invention
The present invention relates to an interchangeable lens and a camera body and, in particular, to a technology for communication between the interchangeable lens and the camera body.
2. Description of the Related Art
In recent digital cameras, cameras capable of high-quality video imaging of a Full-HD (High Definition) video or the like have been widespread with increasing speed of an imaging element. Similarly, a camera with an interchangeable lens is also capable of high-quality video imaging. In a camera with an interchangeable lens, in order to perform image processing on a video according to lens characteristics, it is preferable for a camera body to acquire a state (for example, focus position, diaphragm information, or zoom information) of the lens for each frame during video imaging.
Further, there is conventionally a communication method in which a camera body sends a request (request signal) to an interchangeable lens periodically regardless of a frame of a video so as to confirm whether there is a change in a lens state, and the interchangeable lens sends a response (response signal) regarding the lens state of an item in which there is a change, to the camera body (request-response scheme).
In WO2009/139118A, communication using a request-response scheme is disclosed. In this request-response scheme, necessary information can be acquired when necessary. Further, the request-response scheme is effective in a case in which a camera body does not require lots of information. Cases in which the camera body does not require lots of information include, for example, a case in which the camera body is set to preferentially perform communication for lens driving and control, a case in which a live view display mode is set, and a case in which a video recording mode is set and a large amount of information is not necessary for image processing of a video.
Further, in JP2012-58524A, a technology regarding communication between a camera body and an interchangeable lens through first and second transmission paths has been proposed. In this technology, the first transmission path is used for unidirectional communication, and the second transmission path is used for bidirectional communication.
However, in a case in which a point image restoration process is performed as image processing, lots of lens information such as an F value (diaphragm information), zoom information, and a focus position is necessary for each frame on which the point image restoration process is performed. In particular, 3 pieces of information including the F value, the zoom information, and the focus position are important.
JP2012-505562A discloses that a point image restoration process is performed on an acquired image. Here, the point image restoration process is a process of canceling out degradation of the image by applying a restoration filter (inverse filter) produced based on a point spread function to captured image data. That is, the point image restoration process is a process of performing image processing based on the point spread function (PSF) on a captured image of which the image quality has deteriorated, to recover the image quality, in which the image deterioration caused by aberration or the like is represented by the point spread function.